Up to now, operational amplifiers that amplify signals have been known. Japanese Unexamined Patent Application Publication No. 2006-319388 discloses, in FIG. 1 thereof, an example in which a circuit in which a DMOS of an on-resistance having a temperature dependence and a resistor having a temperature dependence opposite to that of the on-resistance of the DMOS are connected in series to each other is combined with the operational amplifier to reduce the temperature dependence of a gain of the operational amplifier circuit.
Japanese Unexamined Patent Application Publication No, 2007-158771 discloses, in FIG. 1 thereof, an example of configuration in which a nonvolatile memory that stores a control value of a switch designed such that anon-resistance of the switch becomes a resistance, value that allows the temperature dependence of an overall system to be canceled therein is combined with an operational amplifier to reduce the temperature dependence of the gain of the operational amplifier circuit.